Zoology Exam 2 Chapter 13 Cnidarians and Ctenophorans (Roelke) (UTA)

What do ALL Cnidaria have?

cnidocytes

What are specialized organelles that require slight stimulation to fire a chemical projectile containing toxin?

nematocysts

Which phylum has the longest fossil history of any animal?

phylum cnidaria

What is the fastest animal motion recorded?

nematocysts shooting out

What is the preferred environment for cnidarians?

shallow, warm water.

Which symbiotic relation is where both individuals benefit?

mutualism

Which symbiotic relationship is where one individual benefits, and one experiences no effect?

commensalism

Which symbiotic relationship is where one individual benefits, the other experiences a loss?

parasitism

Coral reefs are the most diverse aquatic ecosystem it is ____% of all marine species.

50%

Cnidarians are _____blastic with _____.

diploblastic with mesoglea

Is cnidarian's digestion intercellular or extracellular?

extracellular

Describe the nervous system of cnidarians?

simple nerve net.

What distinct life stage do most coral spend the majority of their lives in?

polyps

Which life stage do jellyfish spend the majority of their lives in?

medusa

How do polyps reproduce?

asexually by budding, fission or pedal laceration.

Which type of symmetry do medusae exhibit?

tetramerous

Which structure in medusae is for orientation?

statocysts

Which structures in medusae are for light reception?

ocelli

How do polyps reproduce differently from medusae?

polyps reproduces asexually, medusae reproduces sexually

What are some reasons that some cnidarians spend all their time in the polyp stage and some all their time in the medusae stage?

phylogenetic constraint, true loss of character state, and it is all based on niches.

What are the body walls in cnidarians?

outer epidermis, inner gastrodermis and the mesoglea in between.

True or False cnidarians have true muscle cells?

false cnidarians have no true muscle cells.

Mesoglea which covers the body is the thickest in the ______, and the thinnest in the _____.

thickest in the stalk, thinnest in the tentacles.

What job does the mesoglea fill?

gives support through hydrostatic pressure so it acts like an elastic skeleton,

What is the "jelly" in a jellyfish?

mesoglea

During development what is the cnidocyte called?

cnidoblast

What happens after the cnidae (organelles) are discharged?

the cell is then resorbed

What is the lid that covers the nematocyst?

operculum

How does the chitin like nematocyst operate?

using hydrostatic pressure differences

What is the trigger of the cnidocytes?

cnidocil, a modified cilium

What is the end of "mouth" or mouth tube called in cnidarians?

manubrium

How do corals usually supplement their diet?

with symbiotic algae

Does the nerve net of cnidarians contain myelin?

no it doesn't contain any myelin

Describe the transmission in the nerve net of cnidarians?

two way transmission

Though there is no centralization in cnidarians, some may have rhopalia which are?

clusters of sensory cells, precursors to centralization

In the polyp stage of class hydrozoa which terms is for the base like a root?

hydrorhiza

What is the term for covered polyps?

thecate

What is the term for naked polyps?

athecate

In the medusa form of class hydrozoa what is the term for the margin of the bell that projects inward?

velum

In medusas of class hydrozoa what is the developmental layer from ectoderm that is unique to hydrozoa?

entocodon

What does entocodon differentiate into?

muscles

Where do the Hydra sp. live?

underside of aquatic leaves

Which species is described as a slender stalk with tentacles at one end and a basal disc for attachment?

hydra sp.

For the hydra what is the term for the conelike structure which the mouth is on top of?

hypostome

In Hydra which cells secrete the adhesive that allows the organism to attach, and are found around the foot?

gland cells

In Hydra which cells are for covering and contraction?

epitheliomusclar cells

What structure does the man o' war use for floatation?

pneumatophore

What is the term for the man-o-war's fishing tentacles?

dactylozooids

Which class of cnidarians contains most of the jellyfish?

class scyphozoa

Which cnidarian class is describe, no velum, margin of umbrella is scalloped with lappets, and has rhopalia between the lappets?

class scyphozoa

In class scyphozoa which side is the mouth on?

sumbrellar side

Class scyphozoa has a ______ with four frill oral arms?

manubrium